White Chicago blues guitarist Michael Bloomfield got the shock of his young life when he was traveling to a gig with his hero Muddy Waters, and Waters started talking about how much he loved to suck cock. It took a while for Bloomfield to figure out that Waters was using cock to refer to a woman's vulva, not a man's penis.

African slaves likely picked up a 17th-century English slang use of "cock" as a passive verb, as in "to want cocking" or "to get cocked." By 1915, when Muddy Waters was born in Rolling Fork, Mississippi, "cock" was a common term for female genitalia among people living in the Delta. A penis was a "cock opener."

In "On the Wall," blues singer Louise Johnson bragged:

Well, I'm going to Memphis, stop at Church's Hall
Show these women how to cock it on the wall

Here, "to cock it on the wall" means to have sex up against the outside wall of the juke joint. Johnson intended to show up the prostitutes who hung around waiting to indulge the men stepping out of the juke for a pleasure break.

Today, the use of "dick" (a variant of "prick") to refer to the penis is still more common among African American speakers than "cock." I interviewed Bob Margolin — who played guitar in the Muddy Waters Band from 1973 to 1980 — for my book The Language of the Blues: From Alcorub to Zuzu, and he confirmed that Waters used the word cock "when he was talking about pussy." He added that Waters was a dignified guy who only used such language around close friends.

On the other hand, whenever Waters wasn't pleased with Margolin's playing, he would growl, "Don't ever play it like that again, it makes my dick sore."

"Nut" is another term that switches genders in the blues. It's slang for testicles, but can also refer to the clitoris or to having an orgasm, as in "busting a nut" or "getting a nut."

"Lemon" is a gender-shifter, too. A woman may promise a male lover, "I'll squeeze your lemon until the juice runs down your leg," yet in "Dirty Mother for You," Memphis Minnie sang:

You done squeezed my lemon
Now you done broke and run

In the African ideograms called nsibidi, the color yellow represents the life force. Shango, the Yoruba thunder god, is often depicted squeezing his life-giving lemon, while pointing with his other hand to the sky — just like Michael Jackson and a host of rappers.

The mythic third king of the Yoruba, Shango wreaks vengeance upon those who have committed moral transgressions. He is Joe, the betrayed lover with a gun in his hand in the Hendrix hit "Hey Joe." He's an enslaved warrior plotting vengeance, expressed metaphorically in so many early blues songs about throwing off the chains of "love" and murdering a cruel, unfaithful lover.

Imagine being fully engaged in your work, your religion, family life, art, music, politics and lively debates with friends one day, and finding yourself a few months later, after a horrific journey, the prisoner of an alien culture. With masters who demand, on pain of death, that you forsake your language, songs and dances; worship their God; and plow their endless fields. Africans in the Americas became masters of metaphor and euphemism.

"Riding" as a euphemism for sexual intercourse was common in English for centuries, but the rider was typically male. In the blues, though, a rider can be of either sex. Both male and female singers sing the traditional song "C.C. Rider," for example; they just change the gender of the rider.

C.C. Rider, see what you have done
You made me love you now your man [woman] done come

An "easy rider" is someone who sponges off his or her lover. Bessie Smith made her feelings clear about one such man in "Rocking Chair Blues":

Easy rider, you see I'm going away
I won't be back until you change your ways

Using a condom is "riding with the saddle on." Having sex with several partners in a row is "riding the train" — and the last partner is "the caboose."

"Riding" may have become a gender shifter in Black English because it is also used metaphorically in the African Vodun religion to describe divine possession. Although Vodun was forcibly repressed in the New World — with enslaved priests who dared practice it put to death — this potent religion morphed into the Voodoo religion and Santeria.

The Voodoo/Vodun state of possession is not the phony demon-possession portrayed by Hollywood movies. It's actually the same state of union with the divine that is the goal of most spiritual practices — akin to becoming filled with the Holy Ghost in the Pentacostal tradition, reaching the Buddhist state of nirvana or attaining the yogi's state of divine bliss, samadhi.

The chanting, drumming, singing and dancing of Voodoo ceremonies are efforts to reach higher levels of consciousness. The priest or priestess attempts to invoke a spirit-god to descend the centerpost of the temple and "mount" members of the congregation. A god will only descend to ride the body of a worshipper who is prepared to attain a state of ecstatic union with the divine. The morality implicit in this is stated in the Haitian proverb, "Great gods cannot ride little horses."

The concept of a deity "riding" a worshipper survived slavery to surface in African American Christian churches, where the cry "Drop down chariot and let me ride!" was often heard, as well as "Ride on, King Jesus!" This eventually become "Right on!"

Enslaved Africans en route to the Americas were stripped of everything but their culture and each other. Luckily, their cultural values were strong. They expressed them through the one art that left no artifacts for slave owners to destroy — music. As the Africans became Americans, they created the blues, a music so emotive and rich with possibility that it birthed jazz and rock 'n' roll within decades of its own conception.

They may have arrived here with nothing, but they enriched and vitalized American language and culture beyond measure.